Differential pulse voltammetric studies of ethidium bromide binding to DNA
| Autor: | Poghos O. Vardevanyan, Marine A. Parsadanyan, Hayk Davtyan, Ara P. Antonyan, L. A. Tavadyan, Seyran H. Minasyan |
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| Rok vydání: | 2006 |
| Předmět: |
Pulse (signal processing)
Osmolar Concentration Intercalation (chemistry) Biophysics Analytical chemistry Ionic bonding DNA General Medicine Binding constant chemistry.chemical_compound chemistry Ethidium Electrochemistry Animals Thermodynamics Cattle Differential pulse voltammetry Physical and Theoretical Chemistry Absorption (chemistry) Ethidium bromide |
| Zdroj: | Bioelectrochemistry. 68:48-55 |
| ISSN: | 1567-5394 |
| DOI: | 10.1016/j.bioelechem.2005.03.006 |
| Popis: | The interaction of ethidium bromide (EtBr) with calf thymus DNA is investigated electrochemically with the use of differential pulse voltammetry (DPV) at two different ionic strengths of a solution (0.154 M and 0.02 M [Na + ], pH 7.0). It is revealed that EtBr binds with DNA in more than one way. The appropriate values of constants ( K ) and number site sizes ( n ) of EtBr binding to DNA are determined. The values of binding constants are equal to 1.9 · 10 6 and 5.6 · 10 5 M − 1 , and number site sizes to 9 and 3.6 for strong interactions at ionic strengths of solutions 0.02 and 0.154 M Na + at 28 °C, respectively. For a weaker interaction, these parameters are equal to 7 · 10 4 and 8 · 10 4 M − 1 and 1.5 and 1 at the mentioned ionic strengths of solutions, respectively. Thus, EtBr interacts with DNA in more than one way—intercalative and electrostatic at low ionic strength, and semi-intercalative and electrostatic at a higher strength of the solution. These results are in good accordance with the ones obtained by spectroscopic (absorption and fluorimetric) methods. |
| Databáze: | OpenAIRE |
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